Hydrochloric Acid → 4-(1-Octenyl)-5-(6-methoxycarbonylhexylidene)-3-(t-butyldimethylsilyloxy) cyclopentanone

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Reaction Steps

3.1 g (6.4 millinmols) of 4-(1-octenyl)-5-(1-hydroxy-6-methoxycarbonylhexyl)-3-(t-butyldimethylsilyloxy)cyclopentanone was dissolved in 40 ml of dichloromethane, and 3.92 g (32.1 mmoles) of dimethylaminopyridine was added. With ice cooling and stirring, 1.0 ml (12.9 mmoles) of methanesulfonyl chloride was added. The mixture was stirred at 0° C. for 5 minutes, and then at room temperature for hours. Furthermore, 0.78 g (6.4 millimoles) of dimethylaminopyridine was added, and the mixture was stirred for 100 minutes. The mixture was poured into 200 ml of 0.5N hydrochloric acid and washed. The aqueous layer was extracted with dichloromethane. The organic layers were combined, washed first with a saturated aqueous solution of sodium bicarbonate and then with a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. The dried product was filtered, concentratd and subjected to silica gel column chromatography (silica gel 150 g; eluent, hexane:ethyl acetate=20:1 →7:1) to give 1.83 g (yield 61%) of 4-(1-octenyl)-5-(6-methoxycarbonylhexylidene)-3-(t-butyldimethylsilyloxy) cyclopentanone. The spectral data of this compound were as follows.

Provenance & Evidence